plasma-framework/widgets/widget.h

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/*
* Copyright (C) 2007 by Alexander Wiedenbruch <mail@wiedenbruch.de>
* and Matias Valdenegro <mvaldenegro@informatica.utem.cl>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License version 2 as
* published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef WIDGET_H_
#define WIDGET_H_
#include <QtGui/QGraphicsItem>
#include <QtCore/QRectF>
#include <QtCore/QSizeF>
#include <plasma/widgets/layoutitem.h>
#include <plasma/plasma_export.h>
namespace Plasma
{
class Layout;
/**
* Base class for all Widgets in Plasma.
*
* @author Alexander Wiedenbruch and Matias Valdenegro.
*
* Widgets are the basis for User Interfaces inside Plasma.
* Widgets are rectangular, but can be in any visible shape by just using transparency to mask
* out non-rectangular areas.
*
* To implement a Widget, just subclass Plasma::Widget and implement at minimum, sizeHint() and paint()
*/
class PLASMA_EXPORT Widget : public QGraphicsItem,
public LayoutItem
{
public:
/**
* Constructor.
*/
explicit Widget(QGraphicsItem *parent = 0);
/**
* Virtual Destructor.
*/
virtual ~Widget();
/**
* Returns a bitmask with the directions that this Widget can be expanded.
*/
virtual Qt::Orientations expandingDirections() const;
/**
* Returns the minimum size of this Widget and it's contents.
*/
virtual QSizeF minimumSize() const;
/**
* Returns the maximum size of this Widget.
*/
virtual QSizeF maximumSize() const;
/**
* Returns true whatever this Widget can use height-for-width layout management,
* false otherwise.
*/
virtual bool hasHeightForWidth() const;
/**
* Returns the corresponding height for a given width.
* @param w Width
*/
virtual qreal heightForWidth(qreal w) const;
/**
* Returns true whatever this Widget can use width-for-height layout management,
* false otherwise.
*/
virtual bool hasWidthForHeight() const;
/**
* Returns the corresponding width for a given height.
* @param h Height
*/
virtual qreal widthForHeight(qreal h) const;
/**
* Returns the geometry of this Widget, in parent coordinates.
*/
QRectF geometry() const;
/**
* Returns the geometry of this Widget, in local coordinates.
*/
QRectF localGeometry() const;
/**
* Sets the geometry of this Widget.
*/
void setGeometry(const QRectF &geometry);
/**
* Propagates the geometry information to associated layouts and other Widgets.
*/
void updateGeometry();
/**
* Invalidates the geometry information.
*/
virtual void invalidate();
/**
* Returns the most appropiate size of this Widget to hold it's contents.
*/
virtual QSizeF sizeHint() const;
/**
* Returns the size of this Widget.
*/
QSizeF size() const;
/**
* Returns the bounding rectangle of this Widget.
*/
virtual QRectF boundingRect() const;
/**
* Resizes this Widget.
* @param size New size
*/
void resize(const QSizeF &size);
/**
* Resizes this Widget.
* @param w New width
* @param h New height
*/
void resize(qreal w, qreal h);
/**
* Sets the Layout that will manage this Widget's childrens.
*/
void setLayout(Layout *l);
/**
* Returns the Layout associated with this Widget.
*/
Layout *layout() const;
/**
* Returns the parent of this Widget.
*/
Widget *parent() const;
/**
* Changes the parent of this Widget.
*/
void reparent(Widget *w);
/**
* Appends a child Widget to this Widget.
*/
void addChild(Widget *w);
/**
* Paint function. Reimplement to draw on this Widget.
*/
virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = 0);
private:
class Private;
Private *const d;
};
} // Plasma namespace
#endif